Polyphosphoric acid resistant hydrogen sulfide scavenger for use in asphalt applications

Abstract

A method and composition for reducing hydrogen sulfide generated or emitted from an asphalt composition are disclosed. In certain aspects, a method for reducing hydrogen sulfide emissions from an asphalt composition is provided wherein an additive is mixed with the asphalt composition and the additive is a copper-based complex. The asphalt composition can include asphalt and an asphalt modifying acid. The copper-based complex can comprise copper carboxylate. The copper carboxylate can be an oil-soluble metal organic.

1 . A method for reducing hydrogen sulfide emissions from an asphalt composition, the method comprising:
 mixing an additive with the asphalt composition wherein the additive comprises a copper-based complex.   
     
     
         2 . The method of  claim 1 , wherein the asphalt composition comprises asphalt and an asphalt modifying acid. 
     
     
         3 . The method of  claim 2 , wherein the hydrogen sulfide is one or more of latent hydrogen sulfide, hydrogen sulfide produced by cracking and hydrogen sulfide produced by regenerative processes caused by the asphalt modifying agent being added to the asphalt composition. 
     
     
         4 . The method of  claim 2 , wherein the asphalt modifying acid is polyphosphoric acid. 
     
     
         5 . The method of  claim 2 , wherein the asphalt modifying acid is an inorganic acid. 
     
     
         6 . The method of  claim 5 , wherein the inorganic acid is phosphoric acid or a phosphonate derivative. 
     
     
         7 . The method of  claim 2 , wherein the asphalt modifying acid is a salt or organic ester of an inorganic acid. 
     
     
         8 . The method of  claim 7 , wherein the salt is sodium phosphate. 
     
     
         9 . The method of  claim 1 , wherein the copper-based complex comprises one or more components from the group consisting of copper carbonate, copper hydroxide and copper oxide. 
     
     
         10 . The method of  claim 1 , wherein the copper-based complex comprises copper carboxylate. 
     
     
         11 . The method of  claim 10 , wherein the copper carboxylate is an oil-soluble metal organic. 
     
     
         12 . The method of  claim 1 , wherein the copper-based complex is formed by reacting copper with an organic acid and diluting the resultant mixture with an organic solvent. 
     
     
         13 . A method for reducing hydrogen sulfide emissions from an asphalt composition, the method comprising:
 mixing an additive with the asphalt composition wherein the additive comprises an iron-based complex.   
     
     
         14 . The method of  claim 13 , wherein the iron-based complex comprises one or more components from the group consisting of iron carbonate, iron hydroxide and iron oxide. 
     
     
         15 . The method of  claim 13 , wherein the iron-based complex comprises iron carboxylate. 
     
     
         16 . The method of  claim 15 , wherein the iron carboxylate is an oil-soluble metal organic. 
     
     
         17 . A composition comprising an asphalt and an additive wherein the additive comprises a copper-based complex. 
     
     
         18 . The composition of  claim 17 , wherein the copper -based complex comprises one or more components from the group consisting of copper carbonate, copper hydroxide and copper oxide. 
     
     
         19 . The composition of  claim 17 , wherein the copper-based complex comprises an oil soluble copper carboxylate. 
     
     
         20 . A composition comprising an asphalt and an additive wherein the additive comprises a iron-based complex. 
     
     
         21 . The composition of  claim 20 , wherein the iron-based complex comprises one or more components from the group consisting of iron carbonate, iron hydroxide and iron oxide. 
     
     
         22 . The composition of  claim 20 , wherein the iron-based complex comprises an oil soluble iron carboxylate. 
     
     
         23 . A method for reducing hydrogen sulfide emissions from an asphalt composition, the method comprising: mixing an additive with the asphalt composition wherein the additive comprises a mixture of iron and copper complexes.